fincatn -F 16 em diu: WARNING: Not enough clusters for a 16 bit FAT!mThe filesystem will be misinterpreted as having a 12 bit FAT without mount option "fat=16".

fico -F 32 i es formata

3) Mount the partition

$ sudo mount /dev/sdc1 /mnt

4) To setup Grub to boot from the USB drive, copy Grub's working files, namely, stage1, stage2 etc, to the partition

mkdir -p /mnt/boot/grub
cp -r /boot/grub/* /mnt/boot/grub

5) Edit /mnt/boot/grub/device.map and set:

(hd0) /dev/sdc
(hd1) /dev/sda
(hd2) /dev/sdb

6)

sudo grub-install --root-directory=/mnt --no-floppy '(hd0)'
Installation finished. No error reported.
This is the contents of the device map /mnt/boot/grub/device.map.
Check if this is correct or not. If any of the lines is incorrect,
fix it and re-run the script `grub-install'.
(hd0) /dev/sdc
(hd1) /dev/sda
(hd2) /dev/sdb